The most common available pipefitting is fitted with NPT, capable of circumventing safety valves! NPT’s are no longer found on Reduced Pressure Zone Valves (RPZ).
T&P Relief Valves were not the only safety devices required by code featuring this simple circumvention.
Remember your introduction to Backflow Prevention?
What is this air gap fitting all about?
Backflow Preventers are Code required Safety Valves used to protect the domestic water from pollution and contamination. Early on the Relief Valves on RPZ’s began to leak and drip. Unknowing individuals began plugging the relief valves (view 4th picture down). Much worse the NPT thread made it easy for plumbers to connect the Relief Valves of the Backflow Prevention Devices directly into the sewer (building drain).
Never plug the relief since this will render the RPZ nothing more than a low hazard Double Check Valve. Never tie a domestic water line into a sewer line. Direct cross connections are not allowed because people could get sick, worse yet die.
During the 1970’s the Codes and Standard committee meetings were blazing with the controversial situation of NPT’s on the water system Safety Relief Valves of the RPZ Prevention Devices.
Money was not the issue, safety was! The industry was required to remove the NPT’s. Pictured to the left are just samples of the old style NPT and the new style – now required to have a special air gap fitting.
INDUSTRY CHANGE
Public Safety changed Codes for RPZ’s.
WHAT ABOUT WATER HEATER SAFETY? THE CHOICE IS YOURS!